Field
Embodiments of the inventive concepts relate in general to lithography apparatuses used in a lithography process, and in particular to a pellicle capable of preventing internal thermal accumulation generated by the high energy of light used in a lithography process, including an extreme ultra-violet (EUV) lithography process.
Description of Related Art
Devices, including semiconductor chip devices, may be at least partially manufactured via a process which includes lithography. For example, a pattern of material may be formed on a semiconductor chip wafer, as part of manufacturing a semiconductor chip device, via a lithography process. The lithography process may include applying a pattern of light on to a layer of photoresist material (“photoresist layer” on a wafer. The photoresist material upon which the applied light is incident may be modified by the light. The light is applied to the photoresist layer in a pattern, and a portion of the photoresist layer may be modified according to the pattern. As a result, upon application of the lithography process to a wafer that includes a photoresist layer, the wafer may include a layer of photoresist material that includes a pattern of modified photoresist material in the photoresist layer. The pattern of modified photoresist material may correspond to the pattern of the light applied to the photoresist layer in the lithography process. Subsequent to the lithography process, the modified photoresist material may be removed in a process which does not remove the unmodified photoresist material. In some cases, the unmodified photoresist material may be removed in a process which does not remove the modified photoresist material. As a result of removal of at least some of the photoresist material, the wafer may include a layer of photoresist material which extends in a pattern according to the pattern of light used in the lithography process.
In some cases, a lithography process includes an extreme ultraviolet (EUV) lithography process. An apparatus configured to implement an EUV lithography process to a device, also referred to herein as an Extreme ultra-violet (EUV) lithography apparatus, may include an EUV optical system applying EUV light to a wafer and a reticle in which an optical pattern is formed. As a result, EUV light applied to a surface of the water may include aerial image information corresponding to the optical pattern, and an aerial image corresponding to the optical pattern may thus be formed on the wafer.
In some cases, to protect the optical pattern of the reticle from external factors, the EUV lithography apparatus may include a pellicle. The pellicle may include a membrane covering the optical pattern of the reticle and a frame supporting the membrane. Light having high energy applied by the EUV optical system may pass through the membrane of the pellicle.
In some cases, the pellicle may incur damage. Such damage may result in a degrading of the EUV lithography apparatus in which the pellicle is included, thereby adversely affecting the EUV lithography process implemented by the apparatus.